[PATCH 2/2] Documentation/sparse: Add hints about __CHECKER__

[Bjorn Helgaas <helgaas@kernel.org>]

From: Bjorn Helgaas <bhelgaas@google.com>

Several attributes depend on __CHECKER__, but previously there was no clue
in the tree about when __CHECKER__ might be defined.  Add hints at the most
common places (__kernel, __user, __iomem, __bitwise) and in the sparse
documentation.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
 Documentation/dev-tools/sparse.rst | 2 ++
 include/linux/compiler_types.h     | 1 +
 include/uapi/linux/types.h         | 1 +
 3 files changed, 4 insertions(+)

diff --git a/Documentation/dev-tools/sparse.rst b/Documentation/dev-tools/sparse.rst
index 02102be7ff49..dc791c8d84d1 100644
--- a/Documentation/dev-tools/sparse.rst
+++ b/Documentation/dev-tools/sparse.rst
@@ -100,3 +100,5 @@ have already built it.
 
 The optional make variable CF can be used to pass arguments to sparse.  The
 build system passes -Wbitwise to sparse automatically.
+
+Note that sparse defines the __CHECKER__ preprocessor symbol.
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index 3c1795fdb568..4b3915ce38a4 100644
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -4,6 +4,7 @@
 
 #ifndef __ASSEMBLY__
 
+/* sparse defines __CHECKER__; see Documentation/dev-tools/sparse.rst */
 #ifdef __CHECKER__
 /* address spaces */
 # define __kernel	__attribute__((address_space(0)))
diff --git a/include/uapi/linux/types.h b/include/uapi/linux/types.h
index 71696f424ac8..c4dc597f3dcf 100644
--- a/include/uapi/linux/types.h
+++ b/include/uapi/linux/types.h
@@ -19,6 +19,7 @@
  * any application/library that wants linux/types.h.
  */
 
+/* sparse defines __CHECKER__; see Documentation/dev-tools/sparse.rst */
 #ifdef __CHECKER__
 #define __bitwise	__attribute__((bitwise))
 #else
-- 
2.25.1